Hello Michael, >> memory reduction (~20%) by doing this for eiffel. But Boehm-Weisser >> scans everything conservative and not only the heap like ruby. MN> Hm, my understanding of Ruby's GC is that it scans the stack MN> conservative (meaning that all values on the stack that look like MN> references to memory are handled as references), but not the heap (how MN> could you conservativly scan the heap?). But probably I misunderstood you. Yes. It was a typo i meant "not only the stack like ruby". Sorry for the confusion. -- Best regards, emailto: scholz at scriptolutions dot com Lothar Scholz http://www.ruby-ide.com CTO Scriptolutions Ruby, PHP, Python IDE 's